ARS | Publication request: Definition of the Escherichia coli O157:H7 proteome under nutrient-limiting conditions to identify targets for efficacious cattle vaccines

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 27, 2011
Publication Date: October 7, 2011
Citation: Kudva, I.T., Griffin, R.W., Krastins, B., Sarracino, D.A., Calderwood, S.B., John, M. 2011. Definition of the Escherichia coli O157:H7 proteome under nutrient-limiting conditions to identify targets for efficacious cattle vaccines [abstract]. 71st Annual Meeting of the North Central Branch of the American Society for Microbiology. October 7-8, 2011, Des Moines,Iowa. 62:149.

Technical Abstract: In this study, the Type III Secretion System (TTSS) proteins considered critical for Escherichia coli O157 (O157) adherence to the follicle-associated epithelial (FAE) cells at the bovine recto-anal junction (RAJ), did not appear to contribute to O157 adherence to the RAJ squamous epithelial (RSE) cells that also constitute this primary site of O157 colonization in cattle. Hence, to identify proteins that could facilitate adherence of O157 to bovine RSE cells, we defined the proteome of O157 cultured in DMEM (the same growth conditions used to evaluate O157 adherence to RSE cells) both to reflect in vivo nutrient-limiting conditions, and to closely parallel those conditions used for the preparation of the cattle-use approved, TTSS-protein based O157 vaccine (Bioniche). The O157 proteome as expressed in DMEM (DMEM-proteome) was analyzed using GeLC-MS/MS, and comprised 686 proteins including, (i) proteins that localized to all cellular compartments, and mapped to the ‘backbone’, as well as the ‘O island’ and ‘pO157’ regions of the O157 genome,(ii) previously identified virulence factors and TTSS proteins,(iii)proteins that comprised the cattle and human O157 immunome as reported by us in previous studies (iv) proteins that were orthologs of adhesins in distantly related pathogens; and (v) numerous unknown/hypothetical secreted and outer membrane proteins. Experimental identification of a subset of proteins in the O157 DMEM-proteome that mediate O157 attachment to bovine RSE cells, and their optimal delivery to the mucosal immune system is likely to result in highly efficacious anti-adhesion vaccines.